This article describes the python script which automatically installs and configures CARP for UNIX (FreeBSD) and UCARP for Linux (Ubuntu, CentOS6 or CentOS7) servers. The script requires an IP address, login, password, virtual IP and CARP password as input parameters. Determination of the type of operating system is performed automatically.

• The test environment consists of Ubuntu, CentOS6, CentOS7, FreeBSD servers in which the CARP/UCARP will be configured. Each type of OS has 2 machines:

  Ubuntu          CentOS6         CentOS7         FreeBSD
  172.16.100.10   172.16.100.11   172.16.100.12   172.16.100.13
  172.16.100.20   172.16.100.21   172.16.100.22   172.16.100.23
  
  VIP: 172.16.100.100
  

• Only machines of one type of OS can be configured at a time:

• Note: The python script uses fabric library which requires BASH to be installed on all FreeBSD machines. Please use the following commands:

  # pkg install -y bash
  # echo "fdesc /dev/fd  fdescfs  rw  0  0" >> /etc/fstab ; mount -a
  # chsh -s bash root ; cp /usr/local/bin/bash /bin/
  

Execute script to configure servers.

• FreeBSD:

• Ubuntu:

• CentOS6:

• CentOS7:

• You can test the system by shutting down the master node while pinging the VIP. Only one ping should be lost.

If you try to use different types of operation systems for master and slave nodes, you will get the following notification and script will not perform the installation.

• Try with FreeBSD and Ubuntu servers:

• Try with Ubuntu and CentOS6 server:

• Try with CentOS6 and CentOS7 server:

• Use the following commands to download and execute code files:

  # git clone https://github.com/jamalshahverdiev/carp-ucarp-unix-linux.git
  # cd carp-ucarp-unix-linux
  # ./carp-ucarp.py